The present invention relates to a tremolo unit and an electric guitar having the tremolo unit. More specifically, the present invention relates to a tremolo unit having a tremolo arm, which tremolo arm has excellent operability and facilitates height adjustment and torque adjustment. The present invention also relates to an electric guitar having the tremolo unit.
In some conventional tremolo units, a metallic cylindrical member is fixed to a swingable base plate, and a tremolo arm is inserted at the proximal end portion to the cylindrical member. In this type of tremolo unit, the tremolo arm is rotatable, so that a player can rotate the grip of the tremolo arm to a position where the tremolo arm opposes the strings of an electric guitar to change the tension of the strings during playing of the guitar. Meanwhile, when the tremolo unit is not used, the grip of the tremolo arm turns downward by its own weight, so that the grip can be cleared away to a position where it does not interfere with playing of the guitar.
However, in this arrangement, since the tremolo arm is merely inserted into the cylindrical member, it is impossible to adjust the height of the tremolo arm relative to the body of the guitar and to keep the grip of the tremolo arm at a position where the tremolo arm opposes the strings. Further, the tremolo arm comes off the guitar in some cases.
Under such circumstances, a tremolo unit is disclosed in Japanese Laid-open Patent Publication No. 2003-005751, in which a tremolo arm is threaded at the proximal end portion, which is screwed into a cylindrical member provided on a base plate to enable height adjustment of the tremolo arm. There is another type of tremolo unit, in which a tremolo arm is pressed at the proximal end portion with a spring or the like to apply frictional resistance to rotation of the tremolo arm.
However, in the threaded tremolo arm described above, although the height of the tremolo arm can be adjusted using the thread, the use of the metallic cylindrical member requires a predetermined clearance between the tremolo arm and the cylindrical member so that the tremolo arm is rotatable. In addition, when the tremolo arm is operated, a great force is applied to its proximal end portion. This makes it impossible to perform adjustment of torque when the tremolo arm is rotated. Besides, the clearance induces interference between metallic parts due to backlash when the tremolo arm is operated and causes impacts and noise, which disadvantageously lower the operability of the tremolo arm. In the case of a tremolo arm that is pressed at the proximal end portion with a spring or the like, although the tremolo arm can be rotated to a desired position and can be held there under friction between the tremolo arm and the cylindrical member, interference between metallic parts attributed to backlash occurs when the tremolo arm is operated to cause impacts and noise, which disadvantageously lower the operability of the tremolo arm.